Navigation
The System
In order to traverse the ice shelf it was necessary to integrate several pieces of software and hardware. With the combination of LabVIEW image processing, an A* route finding algorithm and on-board sensors and compasses it was possibly to achieve a high level of autonomy and adaptability. Janus and Kratos take commands from the Zeus Base Station whilst also being able to override these commands in times of danger or when reaching specified goals.
Moving Across Complex Environments
For each system to cross complex environments and manoeuvre effectively, the robots can be operated either manually, using a controller, or autonomously from a series of compass bearings and distances generated from the IP mapping method. The robots are fitted with a compass, which can be read to turn to a specific bearing and the motors are calibrated to move forward for any distance given. While moving, the ultrasonic sensor mounted on the front of each robot constantly reads the fall distance in front. Utilising the FPGA's customisable I/O allows the robot to easily interrupt the system when necessary. Thus each robot can detect a potential fall in it's path, causing the robot to stop either in front of the hole for the fuel cell or before any fall encountered in the environment.
Iris Image Processing
Mapping
This Iris platform integrates LabVIEW based image processing, image tracking and mapping software. The software takes a picture of the operational environment and maps said environment with a grid of edge detections. This information is sent to the route finding algorithm periodically to ensure a closed-loop of instruction, movement, feedback and then further instruction. This system demonstrates level 5 autonomy. The use of the a 170 degree camera enables the user to map a large area without having the camera too high.
Route finding
The Zeus base-station uses the map created by the overhead camera based Iris IP mapping and applies the A* pathfinding algorithm to plot the shortest route from the current location of each robot to the target destination given by the user. Before creating a path, the process of implementing a safety buffer is executed in order to remove the chance of moving too close to the walls, demonstrating careful handling. The path from the A* algorithm is converted into compass headings and distances, which is sent to each individual robot for them to execute. Upon completing each movement the robot checks its location and moves along the new path generated, which creates closed loop control inside of the navigation system. This element of the navigation is at level 4 autonomy.
Capabilities
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Demonstrate Localization, Route Finding and Navigating on Previously Uncharted Terrains - By combing the route finding algorithm with the continuously updating image processed mapping, the Zeus Base Station is capable of mapping new environments in hugely varied configurations. The on board magnetic compasses provide directional information for both Janus and Kratos allowing them to localise whilst the image processing also confirms the postion of each.
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Providing Control Centre with Mission and Technical Status Updates Including Consideration of Human Factors - Once each movement command is completed by the robots the IP mapping takes a new image of the updated location. This is updated on the Zeus Base Station and feedback to the user via the monitor
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Identifying and Retrieving the Fuel Cell - The LabVIEW based image processing will be able to identify the fuel cell and will inform the rout finder of the location. This will allow Kratos to head there with level 4 autonomy.
